import re

# 正则模式千万千万千万不要打空格！！！！！
bt = 'bat|bit|bet'

m = re.match(bt, 'bat')
if m:
    m = m.group()   # 'bat'

m1 = re.match(bt, 'blt')
if m1:
    print(m1.group())  # AttributeError: 'NoneType' object has no attribute 'group' 匹配失败

m2 = re.match(bt, 'he bit me')
if m2:
    print(m2.group())   # None 从头开始匹配，匹配失败

m3 = re.search(bt, 'he bit me')
if m3:
    print(m3.group())   # bit 搜索成功


s ='@CA_01_284857	M01929:49:000000000-CPK7N:1:1102:15984:3901 1:N:0:ACTGAT'
s = re.match(r'@(\w+)\s+.*', s).group(1)
print(s)